The invention relates to a structural unit comprised of a securing element and a wiper device, in which the wiper device is detachably fastened to the securing element, according to the preamble to claim 1.
Known structural units comprised of a securing element and a wiper device of a vehicle are complex and not user-friendly friendly in terms of their structural design and their ability to be used. This leads to a time-consuming installation or connection of a wiper device to the securing element of a vehicle, possibly with the additional use of installation and/or fastening aids.
The structural unit according to the invention, according to the preamble to claim 1, is characterized in that the detachable connection is embodied as a detent connection. A structural unit embodied in this way is particularly easy to use since with correct positioning of the wiper device in relation to the securing element, an automatically produced detent connection is obtained, by means of which the wiper device is secured in the securing element. Thanks to the automatically produced detent connection, expensive installation and/or fastening aids are not needed to attach the wiper device to the securing element. A detent connection can also reduce the number of structural elements of the structural unit to a minimum so that the structural unit can also be embodied relatively simply in terms of its structural design.
Advantageously, a detent element is embodied on the securing element and elastically engages in detent fashion in a detent seat embodied on a wiper bearing of the wiper device. Since the wiper bearing usually includes a pin-shaped shaped portion and the securing element is normally embodied as a relatively thin-walled plate, it is advantageous for structural and technical operation-related reasons to provide a detent element on the securing element and to equip the wiper bearing with a suitably embodied detent seat.
According to a preferred embodiment, the detent seat is embodied as a circumferential groove which describes a circle that is closed in the longitudinal direction. Embodying the detent seat as a circumferential groove extending in a circle is particularly advantageous for a detent connection since the detent element of the securing element can engage in detent fashion at any point along the circumferential groove. This particularly simplifies the installation of the wiper device onto the securing element since the detent seat of the wiper bearing does not have to be aligned in a particular way in relation to the detent element; it is instead sufficient to merely position the circumferential groove in the plane of the detent element in order to trigger the automatic detent action. The detent element can execute the detent action at any point of the circumferential groove.
Advantageously, the detent element has at least one elastically mobile spring element which has a detent edge which is geometrically fitted to the circumferential groove. Consequently, after production of the detent connection, the spring element extends along at least a part of the circumference of the circumferential groove. Using an elastically mobile spring element, which is geometrically fitted to the circumferential groove, as a detent element is particularly suited for assuring an automatically produced, reliable detent connection when there is a corresponding reciprocal positioning of the detent element and the detent seat. In addition, a detent element embodied in this way is relatively easy to manufacture in terms of production engineering.
According to a preferred embodiment, the securing element is embodied as a securing plate and the spring element is comprised of two elastically mobile, opposing sheet metal parts of the securing plate. A securing element embodied as a securing plate is particularly suitable for producing a detent connection with a wiper bearing that has a detent seat. In order to obtain a reliable and preferably force-symmetrical detent connection between the securing element and the wiper device, the provision is made to produce two opposing, elastically mobile sheet metal parts in the securing plate which, when the wiper bearing of the wiper device is suitably positioned, simultaneously engage in detent fashion in the circumferential groove and secure the wiper bearing and/or the wiper device in a definite rest position.
When in their detent position, the sheet metal parts advantageously protrude from a common plane of the securing plate. With the positioning of the circumferential groove in relation to the spring element, the sheet metal parts are automatically brought into the desired detent position by means of the wiper bearing, which is to be slid partially through the securing plate. Consequently, a particular detent position of the securing plate does not have to be previously produced in order to obtain a reliable and secure detent connection, but rather, the correct detent position of the sheet metal parts is produced automatically by the wiper bearing which, during installation of the wiper device on the securing element, penetrates the securing plate in the vicinity of the structural unit, i.e. between the opposing, elastically mobile sheet metal parts. Consequently, no special installation and/or fastening aids or special installation preadjustments of the sheet metal parts are required.
Preferably, the detent edges of the sheet metal parts are essentially oriented toward each other in their detent position. This assures a correct, definite, and reliable detent engagement of the detent edges of the sheet metal parts in the circumferential groove of the wiper bearing. The term xe2x80x9cdetent edgesxe2x80x9d is understood to mean the region which automatically protrudes into the circumferential groove in the detent position due to the operative elastic restoring force. In this region, the sheet metal parts have a preferably constant wall thickness and produce a form-fitting connection with the circumferential groove. The form-fitting connection between the detent edges of the sheet metal parts and the circumferential groove can be embodied in such a way that after the production of the detent connection and when the sheet metal parts are elastically pivoted out of their detent position, there is an elastic and/or plastic deformation of the detent edges of the sheet metal parts or the walls of the circumferential groove.
According to a preferred embodiment, the respective end surfaces of the detent edges remain in contact with a bottom surface of the circumferential groove in the detent position of the sheet metal parts. The contact of the respective end surfaces of the sheet metal parts with the bottom surface of the circumferential groove in the detent position assures that the sheet metal parts are detent connected to the wiper bearing so that there is no play at least in the depth direction of the circumferential groove or at least in a partial section of the circumference of the circumferential groove. Since the sheet metal parts are disposed opposite each other and are elastically mobile, such a lack of play can be obtained relatively easily in such a way that before assuming their detent position, the sheet metal parts are moved by the wiper bearing counter to an elastic restoring force. This elastic restoring force automatically guides the sheet metal parts into their detent positions and in the detent position, brings the respective end surfaces of the detent edges of the sheet metal parts at least partially into contact with the bottom surface of the circumferential groove.
Advantageously, the sheet metal part can be elastically moved in opposite directions around a pivot axis disposed in the common plane of the securing element. Because of the elastic mobility of the respective sheet metal parts in opposite directions, on the one hand it is possible to obtain an automatically produced detent connection between the respective sheet metal part and the circumferential groove because of the elastic restoring force produced and on the other hand, after the production of the detent connection, an elastic pivoting to a certain degree of the respective sheet metal parts in opposite directions, i.e. toward the plane of the securing plate and away from this plane. Such an elastic flexibility of the securing elements after the production of the detent connection can on the one hand be advantageous with regard to the installation/removal of the wiper device onto/from the securing plate and on the other hand, through suitable structural measures and/or exploitation of specific material properties of the structural parts, it is possible to precisely determine the inward pressing force, which the sheet metal parts exert during installation in order to produce the detent connection with the wiper bearing, and the outward pressing force, which must be exerted during removal of the wiper bearing from the securing plate in order to release the detent connection. Based on such an adjustability of the outward pressing force that must be exerted to release the detent connection, by means of which the sheet metal parts slide out of the circumferential groove, possibly producing a plastic deformation of the sheet metal parts and/or of the circumferential groove, it is also possible to fulfill particular safety requirements such as the requirement that the wiper device be sufficiently flexible and/or release in the event of a collision, particularly when colliding with a human body. In this connection, the outward pressing force that must be exerted to release the detent connection and consequently to release the wiper device, and also the inward pressing force (elastic restoring force) that must be surmounted in order to produce the detent connection can be predetermined by one or more parameters, such as the groove depth of the circumferential groove, or the wall thickness, length, and/or form of the sheet metal parts.
Preferably, in the detent position of the sheet metal parts, the detent edges completely encompass the circumferential groove. This permits a rapid and reliable detent connection to be obtained in a detent region that is as large as possible. If a number of sheet metal parts are provided, which are disposed opposite one another or next to one another and protrude from the plane of the securing plate in the detent position, this produces a particularly stable detent connection since in the detent position, the sheet metal parts are connected to one another and if there is a forced movement in the direction of the plane, the sheet metal parts are subjected to a compressive strain that causes an elastic compression of the sheet metal parts and possibly an additional plastic deformation of the circumferential groove. In the event of such a forced movement in the direction toward the plane, this compressive strain would be produced not only among the sheet metal parts, but also between the circumferential groove and each respective sheet metal part.
According to an alternative embodiment, the wiper device is attached to the securing element of the vehicle by means of a respective detent connections at a number of fastening points that are spaced apart from one another, preferably three of them. The production of the detent connection does not absolutely or exclusively have to be produced at the wiper bearing; additional pin-shaped, preferably cylindrical connecting elements can instead be provided on the wiper device, each with a respective detent seat. The detent connection and/or the structural elements required for it, in particular the detent seat and the associated detent element, can also be adapted to the particular application in terms of their function and their spatial disposition.
Advantageously, the sheet metal parts can be elastically pivoted out of their detent position around their pivot axes, into a direction away from the plane, and when correspondingly pivoted toward the plane, can be subjected to a plastic deformation due to a compressive force produced among the sheet metal parts and/or between each respective sheet metal part and the circumferential groove of the wiper bearing. Due to the plastic deformation of the sheet metal parts and/or the circumferential groove being produced in one movement direction, a relatively stable detent connection is produced between the sheet metal parts and the circumferential groove. Due to a suitable adjustment and/or setting of the compressive force producing the plastic deformation, a desired releasing of the detent connection counter to the plastic deformation forces being produced can be simultaneously achieved.
Preferably, the structural unit for fastening the wiper device to the securing element has an additional fastening device after the production of the detent connection. The detent connection permits a rapid and particularly effective preassembly of the wiper device to the securing element so that if needed, an additional connection, for example by means of a screw connection, can then be produced with particular ease. In this instance, the structural unit thus serves to correctly position and secure the wiper device to the securing element, while a screw connection produces a particularly stable attachment of the wiper device to the securing element.
Other advantageous embodiments of the invention ensue from the characteristics mentioned in the description.